Semifluorinated alkanes are compounds composed of at least one non-fluorinated hydrocarbon segment and at least one perfluorinated hydrocarbon segment. Linear, unbranched semifluorinated alkanes of the general formula CF3(CF2)n(CH2)mCH3, wherein n and m are integers denoting the number of carbon atoms of the respective segment are described for various applications, for example commercially for unfolding and reapplying a retina, for long-term tamponade as vitreous humour substitute (H. Meinert et al., European Journal of Ophthalmology, Vol. 10(3), pp. 189-197, 2000), and as wash-out solutions for residual silicon oil after vitreo-retinal surgery.
Semifluorinated alkanes of the formula CF3(CF2)n(CH2)mCH3 are described in other applications.
WO 2011/073134 discloses solutions of ciclosporin in a semifluorinated alkanes of the formula CF3(CF2)n(CH2)mCH3, optionally in the presence of a co-solvent such as ethanol, wherein the semifluorinated alkane functions as a liquid drug delivery vehicle for ciclosporin for topical treatment of keratoconjunctivitis sicca.
WO2014/041055 describes mixtures of semifluorinated alkanes of the formula CF3(CF2)n(CH2)mCH3 (which may be alternatively expressed as F(CF2)n(CH2)mH). These mixtures are described to be ophthalmically applicable as tear film substitutes or for treating patients with dry eye syndrome and/or meibomian gland dysfunction.
A nomenclature which is frequently used for semifluorinated compounds having linear and unbranched segments is FnHm, wherein F means a perfluorinated hydrocarbon segment, H means a non-fluorinated segment, and n and m define the number of carbon atoms of the respective segment. For example, F3H3 is used for perfluoropropylpropane, CF3(CF2)2(CH2)2CH3, i.e. 1-perfluoropropylpropane.
Semifluorinated alkanes of formula CF3—(CF2)5—CH(CH3)—(CH2)5—CH3 and compositions comprising CF3(CF2)5(CH2)7CH3 and CF3—(CF2)5—CH(CH3)—(CH2)5—CH3 however have not been described, in particular for ophthalmic applications. It is therefore an object of the invention to provide compositions comprising such compounds, in particular in respect of their use in compositions for use in ophthalmic applications.